Office chair with inflatable cellular insert

ABSTRACT

A seat cushion for a chair having a contoured, padded base with an inflatable air cell pad positioned securely within the base and encased within a cover. The air cell pad is optimally located in the base so as to be positioned under the user&#39;s buttocks, particularly under the areas of high-pressure areas on the buttocks of a normally positioned user. The inflatable air cell pad is operatively connected to a pump device positioned on the chair for access by a seated user of the chair. The user can sit on the cushion and inflate or deflate the air cell pad for optimal support and comfort. In one aspect of the invention the pump comprises a bulb and valve combination.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional patent application Ser. No. 60/489,041, filed Jul. 22, 2003.

BACKGROUND OF THE INVENTION

The invention relates generally to office furniture and more specifically to an office chair cushion that provides improved pressure distribution and reduced pressure at high pressure points.

Generally speaking, persons who work in an office environment spend a considerable amount of time in a seated position, usually seated at a desk and often seated for extended periods of time working at a computer terminal. In any event sitting on a chair for long periods of time can result in discomfort in the buttocks, particularly at high pressure points such as the ischia and bony prominences. Although a number of office chairs are available having padding or the like, it would be beneficial to provide an office chair that includes a seat cushion that provides improved pressure distribution and reduced pressure at high pressure points, and even more beneficial if the user can easily and conveniently adjust the pressure distribution and reduction aspects of the cushion.

SUMMARY OF THE INVENTION

One aspect of the invention provides a seat cushion for an office chair having a contoured, padded base with an inflatable air cell pad positioned securing within the base and encased within a cover. The air cell pad is optimally located in the base so as to be positioned under the user's buttocks, particularly under the high-pressure areas of the buttocks of a normally positioned user. The inflatable air cell pad is operatively connected to a pump device located outside the cover for access by the user of the chair. The user can sit on the cushion and then inflate or deflate the air cell pad for optimal support and comfort. The pump can be of any acceptable design. In one aspect of the invention the pump comprises a bulb and valve combination.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or patent application contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 is a perspective view of a representative embodiment of an office chair including a seat cushion of the present invention with the seat cover partial cut away to expose the air cell insert;

FIG. 2 is a perspective view of the seat cushion of the present invention, sans cover;

FIG. 3 is a cross sectional view of the cushion of the present invention taken along line 3-3 of FIG. 2;

FIG. 4 is a side elevational view of the cushion of the present invention;

FIG. 5 is a perspective view of the air cell pad;

FIG. 6 is a pressure map of a prior art office chair seat cushion showing areas of distribution of 50 mm Hg pressure;

FIG. 7 is a pressure map of the seat cushion of the present invention showing areas of distribution of 50 mm Hg pressure;

FIG. 8 is a pressure map of a prior art office chair seat cushion showing areas of distribution of 40 mm Hg pressure;

FIG. 9 is a pressure map of the seat cushion of the present invention showing areas of distribution of 40 mm Hg pressure;

FIG. 10 is a pressure map of a prior art office chair seat cushion showing areas of distribution of 30 mm Hg pressure; and

FIG. 11 is a pressure map of the seat cushion of the present invention showing areas of distribution of 30 mm Hg pressure.

DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION

An office chair, employing a seat cushion of the present invention is indicated generally in FIG. 1 by reference numeral 20. Office chair 20 can be of any acceptable configuration and, at a minimum include a seat cushion 21 and a backrest 23 for a user. Chair 20, as shown, includes a floor engaging base 25 having casters 27 and an upwardly extending pedestal 29 connected to a pan 30 (FIG. 3) on which the seat cushion is mounted. Pedestal 20 generally is connected to pan 30 by a swivel connection (not shown). Backrest 23 includes a rigid frame (not shown) and is attached to the seat pan by an appropriate brace 31 or the like. In most embodiments, base 25, casters 27, pedestal 20, pan 30, brace 31 and the backrest frame are constructed of metal. Hence, the backrest is padded for comfort, as is the seat cushion, as will be explained below, and both are enclosed by an acceptable cover 33. Cover 33 usually is a durable, aesthetically pleasing fabric. In the present invention, certain physical qualities are preferred, particularly the cover of seat cushion 21.

It will be appreciated that chair 20 as shown is a basic configuration for simplicity of description, and the acceptable configurations of a chair employing the seat cushion of the present invention are unlimited. The chair can have a headrest, arm rests, legs, and so forth. Also, it will be pointed out that although the main application of the seat cushion of the present invention is an office chair, the claimed seat cushion can be used in any seating environment. It can be particularly suited to those users where users are seated for extended periods of time, such as chairs in theatres, dentists' chair, chairs in hair salons, barber chairs, and even chairs for home use.

Seat cushion 21, without a cover, is shown in greater detail in FIGS. 2 through 4. Cushion 21 includes a supportive, resilient base 35. Base 35, in an illustrated aspect of the invention, is comprised of polyurethane foam and shaped with appropriate contours to facilitate comfortable seating by the user, as known in the art. Base 35 includes a cut out area or cavity 37 and an air cell pad 39 positioned in cavity 37. In general, cavity 37 is formed in the bottom of base 35 and air cell pad 39 is introduced into the cavity and a foam layer or seal can be secured to the bottom of the base to keep air cell pad 39 in place. In one aspect of the invention the thickness of the foam can range for ½ in to more than 3 inches, preferably 1½ inches to 2 or more. It will be appreciated that foam other than polyurethane foam can be employed, including, but not limited to viscoelastic foam or any other type of material that imparts the functional qualities of a foam.

In alternative embodiments of the invention, cavity 37 can be formed in the top of base 35 with air cell pad 39 introduced from the top. In such an arrangement, there can be a thin layer of foam positioned over the air cell pad or the air cell pad can be covered only by cover 33. In yet another alternative embodiment, the cover can have an opening at the air cell pad, so that the air cell pad is exposed.

Air cell pad 39 is located in base 35 at a position that places the air cell pad under the ischial area of a normally seated user. The ischial tuberosities are the lower portions of the hip bones and usually represent the area of greatest pressure on the buttocks of a seated user. Most discomfort experienced from prolong seating is felt in the buttocks at the ischial area.

In any event, air cell pad 39, shown in detail in FIG. 5, is comprised of a flexible base 40 and an array of individual air cells 42 arranged in rows of air cells across the base. In the illustrated embodiment, each air cell 42 is a preferably an expandable, four fin cell preferably molded from neoprene. Any geometry of cell can be employed however, such as pyramidal shaped, cells having more than four fins, cubes or other useful shapes. The geometry of the air cells, however, should provide minimal resistance to conformity to the shape of the buttocks of the seated user. In a preferred aspect of the invention, the air cells are approximately 2 inches in height. As seen in FIG. 3, the geometry of the air cells 42 in array of air cells provides for a smooth transition between the air cell pad 39 and surrounding base 35. The individual air cells 42 are interconnected so that air introduced into one cell is distributed among the cells so as to equalize pressure within the cells.

As shown in FIG. 5, there is an air conduit 46 connected to one air cell 42 at one end and a pump, shown as bulb pump 48 in FIG. 4, at the other end. Air cell pad 39 preferably can be molded from neoprene in accordance with the teachings of U.S. Pat. No. 4,541,136, which is incorporated herein by reference. Air cell pad 39 also can be made from urethane or PVC or other plastic or moldable materials that can be used to make an air cell.

Base 35 is enclosed in cover 33. In the illustrated embodiment, the top surface of cover 33 should stretch to deform under the seated user, ideally 250% by 170%. It is not necessary for the cover material over the sides of the seat cushion to stretch. The cover material at the top surface preferably also should be breathable. In the illustrated embodiment, the cover also encloses air cell pad 39.

It will be appreciated from the drawings that in the illustrated embodiment, bulb pump 48 is located on one side of seat cushion 21, outside cover 33 so as to be accessible to the user seated on the chair. The pump can be located in any convenient place on the chair as long as it is easily accessible by a seated user and can is in fluid communication with air cell pad 39. The pump actually could be under the cover yet accessible for actuation by depressing the cover and bulb, for example. Pump 48 includes a bulb 50 and push button relief of valve 52. The user can actuate bulb 50 and pump air into the air cell pad and depress push button valve 52 to allow the release of air from the air cell pad. Although the illustrated embodiment employs a bulb pump, it is intended that any acceptable pump be encompassed by the present invention. To achieve optimal benefit of the seat cushion of the present invention, the user sits on the cushion with the ischial area positioned over air cell pad 39. The user then can actuate pump bulb 50 and pump air into the air cell pad until that individual user is comfortable and well supported. The cells 42 deform under the buttocks and thighs to provide a maximum Air Floatation® support surface. The user also can allow air to escape through the valve until he or she reaches a desired immersion into air cell pad 39 to provide customized support surface. This support surface provides superior pressure relief over prior art seat cushions, as shown by pressure mapping illustrated in FIGS. 5 through 11 below. In any event, during use, if the user wants to change the immersion depth or seating characteristics, he or she can open the valve and adjust the air pressure within air cell pad 39.

The pressure maps in FIGS. 5 through 11 are a visual representation of the force distribution on a seat cushion of the present invention versus a prior art office chair seat cushion designed to reduce pressure. The prior art cushion tested is the Ergogenesis Model No. J2507 (Ergogenesis, Navasota, Tex.). The prior art seat cushion is a contoured seat, based upon the concept of zero gravity posture that is designed to disperse the user's body weight over an increased surface area.

In creating the pressure maps approximately 35 to 40 mm Hg pressure was applied to the cushion by a seated load. The darkest areas of the black and white pressure maps, which correspond to the red areas of the color pressure maps, represent the areas of greatest pressure. FIGS. 6 and 7 illustrate the areas of 50 mm Hg pressure resulting from the force load on the prior art seat cushion (FIG. 6) and the cushion of the present invention (FIG. 7). As shown by the pressure maps, areas of resulting 50 mm Hg pressure appear on the pressure map of FIG. 6, whereas none appear on pressure map of FIG. 7.

FIGS. 8 and 9 illustrate the distribution of 40 mm Hg pressure or greater in the respective cushions under the force load. As can be seen in FIG. 8, the pressure map of the prior art cushion illustrates a significant area of pressure of 40 mm Hg or greater, whereas the cushion of the present invention again shows none.

Finally, FIGS. 10 and 11 show the distribution of 30 mm Hg pressure or greater under the force load. The pressure map of the prior art cushion, FIG. 10, shows an even greater area of pressure when measuring pressure of 30 mm Hg or more, whereas the cushion of the present invention, mapped in FIG. 11, shows relatively small areas of pressure of 30 mm Hg or greater under the force load.

It will be appreciated by comparing the darkest areas of the pressure maps in the black and white pressure maps, which correspond to the red color in the color pressure maps, that the seat cushion of the present invention reduces pressure, particularly at the ischial areas when measuring three different pressure distributions under a constant force load.

It will be appreciated that the foregoing description and accompanying drawings illustrate one representative aspect of the invention, including the best mode of working the invention presently known to the inventor. However, the specification should be viewed as illustrative of the broadest aspects of the invention and should not be construed in a limiting sense. 

1. A seat cushion for a chair for support of a seated user, the seat cushion comprising: a padded base; an inflatable air cell pad positioned securely within the base and located in the base so as to be positioned under an area of high pressure on the buttocks of a normally positioned user; a cover enclosing the padded base; and a pump device operatively connected to the air cell pad and positioned for access by the user of the chair so the user can sit on the seat cushion and inflate or deflate the air cell pad with the pump for optimal support and comfort.
 2. The seat cushion of claim 1 wherein the pump comprises a bulb and valve combination.
 3. The seat cushion of claim 1 wherein the padded base comprises a cavity for placement of the air cell pad.
 4. The seat cushion of claim 1 wherein the cover has a stretchable top surface.
 5. The seat cushion of claim 1 wherein the air cell pad comprises a flexible base, an array of individual interconnected air cells on the base, and an air conduit having one end in fluid connection with at least one of the individual air cells and a second end connectable to the pump.
 6. The seat cushion of claim 1 wherein the air cell pad is formed from neoprene.
 7. The seat cushion of claim 1 wherein the padded base is formed from polyurethane foam.
 8. The seat cushion of claim 1 wherein the chair is an office chair.
 9. A seat cushion for an office chair for support of a seated user, the seat cushion comprising: a contoured foam base having a cavity formed therein; an inflatable air cell pad positioned securely within the cavity and located in the base so as to be positioned under an area of high pressure on the buttocks of a normally positioned user, said air cell pad comprising a flexible base, an array of upstanding, interconnected air cells on the base and, an air conduit in fluid communication with at least one of the individual air cells; a cover enclosing the padded base; and a pump device operatively connected to the air conduit and positioned for access by the user of the chair so the user can sit on the cushion and inflate or deflate the air cell pad with the pump for optimal support and comfort.
 10. The seat cushion of claim 9 wherein the cavity is formed through a bottom surface of the base.
 11. The seat cushion of claim 9 wherein the cavity is formed through a top surface of the base.
 12. The cushion of claim 9 wherein the air cell pad is formed from neoprene.
 13. A chair for support of a seated user, the chair comprising: a back rest for supporting the back of a the seated user: a seat cushion for seating of the user, the seat cushion comprising a contoured foam base having a cavity formed therein, an inflatable air cell pad positioned securely within the base cavity and located in the base so as to be positioned under an area of high pressure on the buttocks of a normally positioned user, said air cell pad comprising a flexible base, an array of upstanding, interconnected air cells on the base and an air conduit in fluid communication with at least one of the individual air cells; and a cover enclosing the padded base; and a pump device operatively connected to the air conduit and positioned for access by the seated user of the chair so the user can sit on the seat cushion and inflate or deflate the air cell pad with the pump for optimal support and comfort.
 14. The chair of claim 13 wherein the air cell pad is formed from neoprene.
 15. The chair of claim 13 wherein the pump device is a bulb pump having a valve thereon to allow release of air from the air cell pad.
 16. The chair of claim 13 wherein the pump device is enclosed by the cover.
 17. The chair of claim 13 wherein the cavity is formed through a top surface of the foam base.
 18. The chair of claim 17 wherein the air cell pad is covered by a layer of foam.
 19. The chair of claim 17 wherein the cover has an opening therein to expose the air cell pad. 